1. Field of the Invention
This invention relates to a refrigerator provided with a switching valve for switching a flow of refrigerant to one of a plurality of refrigerant passages so that the refrigerant flows through the switched refrigerant passage.
2. Description of the Prior Art
Household refrigerators are generally installed indoors and particularly in a dwelling space. Accordingly, noise reduction has been desired in the refrigerators. Inverters have recently been employed for the purpose of reducing noise produced during operation of the refrigerator. Further, a refrigerating cycle has been improved so that a compressor is driven at low speeds. However, there have been provided refrigerators with a switching valve for switching a flow of refrigerant to one of a plurality of refrigerant passages so that a refrigerant flows through the switched refrigerant passage. The switching valve also produces noise due to a switching operation.
The noise due to the switching operation of the switching valve is produced in the following manner. The switching valve comprises an electromagnetic valve, for example. The electromagnetic valve includes a solenoid producing an attractive force upon energization. When subjected to the attractive force, a valve element of the electromagnetic valve is moved to the side of an attracting element against an urging force of urging means. When the solenoid is deenergized, the urging force moves the valve element in the direction opposite to the attracting element. Thus, a passage of a fluid is opened and closed, or a flowing direction of the fluid is switched.
The valve element of the electromagnetic valve is attracted by the attracting element in a short period of time when a predetermined drive voltage is applied to the solenoid. In this case, the valve element forcibly collides with the attracting element. As a result, a relatively large noise due to the collision is produced at a location away 5 cm from the electromagnetic valve. This noise ranges between 80 and 90 dB (A). The noise produced by the switching valve results from the above-mentioned noise due to the collision of the valve element. The switching valve is often operated according to controlled temperatures in refrigerating and freezing compartments, for example. Moreover, the noise due to the switching operation is relatively louder. Consequently, the noise due to the switching operation of the switching valve is offensive or abnormal to ears of a user.